Kostalius rotundisetis Borovec, 2025

Borovec, Roman, 2025, Two new and one enigmatic genus of Oosomini from South Africa with description of seven new species (Coleoptera: Curculionidae: Entiminae), Zootaxa 5642 (2), pp. 101-126 : 122-123

Kostalius rotundisetis Borovec , sp. nov.

Figs (8–10, 44, 45, 48, 49, 50, 52, 53, 55, 57)

http://zoobank.org/ urn:lsid:zoobank.org:act:6468F5EF-674B-4838-8050-CA279F5D3CFC

Type locality. South Africa, Eastern Cape, Katberg Mts., Katberg Pass .

Type material. Holotype: ♂, RSA, Eastern Cape, Katberg Mts., Katberg Pass env., S 32°27.501′ E 26°39.421′, 1 500 m, 10.xi.2023, Sifting under Ericaceae shrubs, R. Borovec leg. ( NMPC) . Paratypes: 19 specs., same data as holotype ( BMNH, CMNC, MKŠS, RBSC, SANC, TMSA) ; 1 ♂ 1 ♀, South Africa, Eastern Cape c., Katberg Mts., Katberg Pass env., S 32°27.5′ E 26°39.4′, 1 500 m, 1.xii.2018, M. Košťál leg. ( MKŠS) .

Diagnosis. Odd elytral interstriae with regularly rounded, large, conspicuous scales raised from tips of small bumps, scales on pronotum forming one transverse row; rostrum subparallel-sided; epifrons evenly tapered apicad, posteriorly with supraocular lobes covering eyes in dorsal view; funicle with 7 articles.

Description. Body length holotype 3.25 mm, paratypes 2.47–3.25 mm. Body ( Figs 9, 10 ) of very clean specimens brown reddish with darker, black clubs, sparsely covered by perpendicularly erect piliform setae, shortly hooked at apex, not covering integument, 3 across width of one elytral interstria. Elytral interstriae 1, 3, 5 and 7 with single significantly conspicuous row of erect, sparse, regularly rounded, moderately large scales, raised from tips of small bumps, about as wide as interstria, finely longitudinally striate and finely serrated at apical margin, 7–8 along length of interstria 3. Pronotum with transverse row of four closely pressed triplets of identical rounded scales as elytral ones. Anterior margin of pronotum with short row of several slightly smaller rounded scales. Rostrum with row of 6–7 small rounded erect scales on margin of epifrons. Antennal scapes sparsely covered with short, piliform, appressed setae and with conspicuous dense row of erect rounded scales on inner side; funicles with short, semi-erect, piliform setae; clubs in apical half finely densely setose. Femora with short, semi-appressed, narrow setae; tibiae with short, appressed, piliform setae, outer margin with dense row of erect rounded scales; tarsi with short sparse setae. Not artificially cleaned specimens are completely encrustated with not visible appressed vestiture, but with well visible erect rounded scales, scapes and tibiae seeming wider by encrustation.

Rostrum ( Figs 44, 45 ) very short, 1.47–1.56× as wide as long, subparallel-sided with almost straight sides, apically broadly rounded, in lateral view distinctly vaulted. Epifrons distinctly evenly tapered apicad with straight swollen margins, at base 1.32–1.45× as wide as at apex, posteriorly forming large, distinct supraocular lobes completely covering eyes in dorsal view and well visible also in lateral view; epifrons posteriorly separated from head by very shallow transverse furrow in place of posterior eyes margin, dorsally shallowly longitudinally depressed. Antennal scrobes in dorsal view visible only in place of antennal insertions; in lateral view short, enlarged posteriad, directed towards eye but separated from it by narrow squamose stripe. Eyes small, invisible in dorsal view, subcircular in lateral view, placed in ventral half of head.

Antennae ( Figs 9, 10 ) with scape 2.4–2.6× as long as wide and 1.4–1.5× as long as funicle, at apex 1.6–1.7× as wide as club. Funicle with 7 articles; article 1 1.4–1.5× as long as wide and 1.7–1.8× as long as article 2, this is 1.2–1.3× as long as wide; articles 3–6 1.2–1.3× as wide as long; article 7 1.4–1.5× as wide as long; clubs 1.4–1.6× as long as wide.

Pronotum ( Figs 9, 10 ) very wide, 1.66–1.76× as wide as long, slightly narrower than elytra, distinctly constricted behind anterior margin, in anterior half much narrower than in posterior half, widest at midlength; disc with transverse incision in middle, often covered with encrustation; posterior half with transverse row of four small pointed bumps; anterior margin with two smaller bumps; pronotum in lateral view almost flat, decreased in middle, with slightly elevated anterior margin.

Elytra ( Figs 9, 10 ) oval, 1.12–1.17× as long as wide, widest at midlength, with slightly rounded sides. Odd interstriae with sparse, low, pointed bumps as wide as interstriae, 7–8 across length of interstria, with distinct erect rounded seta on top. Striae under encrustation punctured; interstriae smooth. Elytra in lateral view flat.

Abdominal ventrites 1.08–1.13× as long as wide ( Fig. 49 ).

Protibiae ( Fig. 48 ) apically subtruncated with fringe of short and fine black setae; meso- and metatibiae with apical surface densely fringed by long black setae. Tibiae often encrustated and distinctly enlarged at middle. Tarsi with tarsomere 2 1.7–1.8× as wide as long; tarsomere 3 1.4–1.5× as wide as long and 1.4–1.6× as wide as tarsomere 2; onychium 0.8–0.9× as long as tarsomere 3; claws somewhat divaricate.

Penis ( Fig. 50 ) subparallel-sided, slightly wider at apical portion, apically somewhat obtuse, with small, well visible rounded tip at middle; in lateral view slender, slightly curved with small apical tip, doubled with small membraneous spine at apex of dorsal side; temones almost twice as long as body of penis; endophallus with two long, parallel sclerites, one straight and very slender, the other much wider, distorted. Tegmen with slender ring bearing two short, translucent parameres; manubrium about twice as long as ring diameter. Sternite IX with spiculum gastrale anteriorly curved and enlarged to small, irregularly oval plate, posteriorly with fused basal arms.

Female sternite VIII ( Fig. 55 ) with small subtriangular plate, slightly longer than wide, with sides slightly concave; apodeme 3.3–3.5× longer than plate, forming basal margin of plate. Gonocoxites ( Fig. 57 ) slender, narrowly subtriangular, evenly tapering apicad with moderately long apical styli. Spermatheca ( Fig. 53 ) with regularly curved short and wide cornu; ramus slightly longer than wide, apically rounded; collum slightly shorter and narrower than ramus, slightly tapering apicad, apically rounded.

Derivation of name. The species takes its name from Latin rotundus, rounded, circular, and seta (saeta), meaning seta (chaeta), which refers to the very specific shape of erect setae on the dorsal surface of the body.

Biology. The type material was sifted below two different Ericaceae shrubs in a pass in an open, not forested habitat.

Distribution. South Africa, Eastern Cape.

Differential diagnosis. Kostalius rotundisetis is easily distinguished from the other species of the genus described in this paper. Distinguishing characters between the two species are stated below.

Figures

FIGURES 9–12. Dorsal habitus.9. Kostalius rotundisetis, encrustated. 10. K.rotundisetis, cleaned. 11. K.sylvaticus, encrustated. 12. K. sylvaticus, cleaned. Not to scale.

FIGURES 44–57. 44–47: Head including rostrum in dorsal and lateral view. 44, 45. Kostalius rotundisetis. 46, 47. K. sylvaticus. 48: Right protibia. K. rotundisetis. 49: Abdominal ventrites. K. rotundisetis. 50, 51: Penis in dorsal view. 50. K. rotundisetis. 51. K. sylvaticus. 52: Tegmen. K. rotundisetis. 53, 54: Spermatheca. 53. K. rotundisetis. 54. K. sylvaticus. 55, 56: Female sternite VIII. 55. K. rotundisetis. 56. K. sylvaticus. 57: Ovipositor. K. rotundisetis. Scale 1.00 mm for 49; 0.50 mm for 44–48; 0.25 mm for 50–57.